CS0-003 Exam Dumps - CompTIA CyberSecurity Analyst CySA+ Certification Exam

The correct answer is C. False negative.

A false negative is a situation where an attack or a threat is not detected by a security control, even though it should have been. In this case, the SIEM rule was unable to detect an attack with nine failed logins, which is below the threshold of ten failed logins that triggers an alert. This means that the SIEM rule missed a potential attack and failed to alert the security analysts, resulting in a false negative.

A false positive is a situation where a benign or normal activity is detected as an attack or a threat by a security control, even though it is not. A true negative is a situation where a benign or normal activity is not detected as an attack or a threat by a security control, as expected. A true positive is a situation where an attack or a threat is detected by a security control, as expected. These are not the correct answers for this question.

Comprehensive and Detailed Explanation From Exact Extract:

The analyst should review PID 768 first because it is the parent process of another suspicious process (PID 1100) and it is also highly suspicious itself due to its unexpected file path.

Why PID 768 is the best first process to review

Path anomaly (strong IoC): Legitimate Windows binaries like calc.exe and cmd.exe are normally found in trusted OS directories (e.g., C:\Windows\System32\). In the table, both CALC.exe and CMD.exe appear in a user’s Documents folder (C:\Users\JDoe\Documents\...). That is a classic sign of masquerading (a malicious binary using a legitimate-sounding name). The All-in-One guide explicitly describes how attackers disguise malicious processes by using legitimate-sounding names and mimicking system processes.

Parent-child relationship (investigation priority): PID 1100 (Documents\CMD.exe) is suspicious, but it is a child of PID 768 (Documents\CALC.exe). Investigating the parent first helps you understand what spawned the suspicious child, what activity preceded it, and whether PID 768 is the root of the execution chain. The All-in-One guide highlights that analysts should examine process parent-child relationships and investigate unexpected dependencies as a way to detect malicious activity:Exact extract (All-in-One Exam Guide): “Analyze process dependencies Examine process parent-child relationships and investigate any unexpected or unusual dependencies that may indicate malicious activity.” It also emphasizes monitoring grandparent/parent/child relationships to detect deviations from normal process hierarchies:Exact extract (All-in-One Exam Guide): “Monitoring the relationships between processes, particularly grandparent, parent, and child relationships, can be a valuable method for detecting unusual activity.”

Abused/LOLBIN context: cmd.exe is a commonly abused Windows utility in attacks. The Sybex Study Guide notes that attackers often abuse built-in tools and that abnormal OS process behavior involving tools like cmd.exe can indicate compromise:Exact extract (Sybex Study Guide): “For Windows systems, a handful of built-in tools are most commonly associated with attacks like these, including cmd.exe…”

Why the other options are less correct

A (533) and B (740) are running from C:\Windows\System32\... which is the expected location for legitimate Windows binaries in normal circumstances, so they’re less suspicious than the copies running from a user Documents folder.

D (1100) is suspicious, but it is a child of PID 768. Investigating 768 first helps determine the origin and execution chain that led to the suspicious cmd instance.

References (CompTIA CySA+ CS0-003 documents / study guides used):

Mya Heath et al., CompTIA CySA+ All-in-One Exam Guide (CS0-003): parent/child process dependency analysis; process hierarchy monitoring; masquerading techniques

Mike Chapple & David Seidl, CompTIA CySA+ Study Guide (CS0-003): abnormal OS process behavior; cmd.exe commonly associated with attacks

Mean time to detect (MTTD) is a metric that measures how quickly an organization can identify a security incident or a malicious actor in the environment. Reducing MTTD can improve visibility and reporting of threats, as well as prevent lateral movement and data exfiltration by detecting them sooner.

The MTTR (Mean Time to Resolution) decreases by 20% is the best possible outcome that this effort hopes to achieve, as it reflects the improvement in the efficiency and effectiveness of the incident response process by reducing analyst alert fatigue. Analyst alert fatigue is a term that refers to the phenomenon of security analysts becoming overwhelmed, desensitized, or exhausted by the large number of alerts they receive from various security tools or systems, such as DLP (Data Loss Prevention) or CASB (Cloud Access Security Broker). DLP is a security solution that helps to prevent unauthorized access, use, or transfer of sensitive data, such as personal information, intellectual property, or financial records. CASB is a security solution that helps to monitor and control the use of cloud-based applications and services, such as SaaS (Software as a Service), PaaS (Platform as a Service), or IaaS (Infrastructure as a Service). Both DLP and CASB can generate alerts when they detect potential data breaches, policy violations, or malicious activities, but they can also produce false positives, irrelevant information, or duplicate notifications that can overwhelm or distract the security analysts. Analyst alert fatigue can have negative consequences for the security posture and performance of an organization, such as missing or ignoring critical alerts, delaying or skipping investigations or remediations, making errors or mistakes, or losing motivation or morale. Therefore, it is important to reduce analyst alert fatigue and optimize the alert management process by using various strategies, such as tuning the alert thresholds and rules, prioritizing and triaging the alerts based on severity and context, enriching and correlating the alerts with additional data sources, automating or orchestrating repetitive or low-level tasks or actions, or integrating and consolidating different security tools or systems into a unified platform. By reducing analyst alert fatigue and optimizing the alert management process, the effort hopes to achieve a decrease in the MTTR, which is a metric that measures the average time it takes to resolve an incident from the moment it is reported to the moment it is closed. Alower MTTR indicates a faster and more effective incident response process, which can help to minimize the impact and damage of security incidents, improve customer satisfaction and trust, and enhance security operations and outcomes. The other options are not as relevant or realistic as the MTTR decreases by 20%, as they do not reflect the best possible outcome that this effort hopes to achieve. SIEM ingestion logs are reduced by 20% is not a relevant outcome, as it does not indicate any improvement in the incident response process or any reduction in analyst alert fatigue. SIEM (Security Information and Event Management) is a security solution that collects and analyzes data from various sources, such as logs, events, or alerts, and provides security monitoring, threat detection, and incident response capabilities. SIEM ingestion logs are records of the data that is ingested by the SIEM system from different sources. Reducing SIEM ingestion logs may imply less data volume or less data sources for the SIEM system, which may not necessarily improve its performance or accuracy. Phishing alerts drop by 20% is not a realistic outcome, as it does not depend on the integration of DLP and CASB or any reduction in analyst alert fatigue. Phishing alerts are notifications that indicate potential phishing attempts or attacks, such as fraudulent emails, websites, or messages that try to trick users into revealing sensitive information or installing malware. Phishing alerts can be generated by various security tools or systems, such as email security solutions, web security solutions, endpoint security solutions, or user awareness training programs. Reducing phishing alerts may imply less phishing attempts or attacks on the organization, which may not necessarily be influenced by the integration of DLP and CASB or any reduction in analyst alert fatigue. False positive rates drop to 20% is not a realistic outcome

SLA (Service Level Agreement) is the best term to describe the document that defines the expectation to network customers that patching will only occur between 2:00 a.m. and 4:00 a.m., as it reflects the agreement between a service provider and a customer that specifies the services, quality, availability, and responsibilities that are agreed upon. An SLA is a common type of document that is used in various industries and contexts, such as IT, telecom, cloud computing, or outsourcing. An SLA typically includes metrics and indicators to measure the performance and quality of the service, such as uptime, response time, or resolution time. An SLA also defines the consequences or remedies for any breaches or failures of the service, such as penalties, refunds, or credits. An SLA can help to manage customer expectations, formalize communication, improve productivity, and strengthen relationships. The other terms are not as accurate as SLA, as they describe different types of documents or concepts. LOI (Letter of Intent) is a document that outlines the main terms and conditions of a proposed agreement between two or more parties, before a formal contract is signed. An LOI is usually non-binding and expresses the intention or interest of the parties to enter into a future agreement. An LOI can help to clarify the key points of a deal, facilitate negotiations, or demonstrate commitment. MOU (Memorandum of Understanding) is a document that describes a mutual agreement or cooperation between two or more parties, without creating any legal obligations or commitments. An MOU is usually more formal than an LOI, but less formal than a contract. An MOU can help to establish a common ground, define roles and responsibilities, or outline expectations and goals. KPI (Key Performance Indicator) is a concept that refers to a measurable value that demonstrates how effectively an organization or individual is achieving its key objectives or goals. A KPI is usually quantifiable andspecific, such as revenue growth, customer satisfaction, or employee retention. A KPI can help to track progress, evaluate performance, or identify areas for improvement.

 The first thing that must be done when starting an investigation is to secure the scene. Securing the scene involves isolating and protecting the area where the incident occurred, as well as any potential evidence or witnesses. Securing the scene can help prevent any tampering, contamination, or destruction of evidence, as well as any interference or obstruction of the investigation.

The discovery of unapproved accounts accessing shared data, along with data discrepancies, strongly indicates unauthorized changes.

Indicators of Unauthorized Changes:

Unexpected user permissions found during audits​.

Modified or deleted data without proper documentation.

Altered system or security configurations, allowing unintended access.

Why Not Other Options?

A. Filesystem Anomaly: This refers to unexpected behavior in the file structure, such as corrupt metadata or missing files, rather than unauthorized user access.

B. Illegal Software: Would involve unlicensed or unauthorized applications, not unauthorized file modifications.

D. Data Exfiltration: If data was removed, it might be exfiltration, but in this case, data modifications were detected instead.

To prevent unauthorized changes, security teams should use:

File Integrity Monitoring (FIM) to detect unauthorized modifications.

Access control audits to verify correct user permissions.

SIEM tools to analyze logs for anomalies.

Data loss prevention (DLP) is a tool that can prevent the exposure of PII outside of an organization by monitoring, detecting, and blocking sensitive data in motion, in use, or at rest.